"unsure of" or "unsure about"--which is right?

Hey everyone,

I'm second, fourth and twenty-guessing myself on this one. Which sentence is correct?

Unsure about his next grade, he studied extra hard.

Unsure of his next grade, he studied extra hard.

Thanks for any help y'all can give me on this. (I want to use 'about' but the original text I'm editing has 'of' there instead. I couldn't find anything in a google grammar search. )

Warmly,
Jenny

Oberon said:

I will jump in here, although I am unsure of the correct answer, meaning I don't know what the correct answer is. I am unsure about my feelings on this subject, meaning I haven't made up my mind. And I could very well be totally wrong, so I'd wait for one of the grammar-wonks to chip in so you can be sure about it. Now I will quit before I get further enmeshed and unsure of myself.

Click to expand...

LOL!!!

That's exactly how I felt So unsure of myself and completely unsure about the grammar rules on this one!

Thanks JJM

Yeah, I'm kind of thinking that must be it--there isn't any real rule about this, it's just preference.

Thanks for chiming in. At least I know it's not something I either didn't learn, totally forgot, or was too dim-witted to discover in the gazillion grammar books I own or on google